1. Field of the Invention
The present invention relates to a circuit for triggering an on-hook and off-hook function of a communication apparatus.
2. Description of the Prior Art
Mobile phones are the most universal mobile communication apparatus currently, but in some situations, users cannot conveniently use mobile phones. For example, when a user is riding a motorbike or driving a car, and there is an incoming call, the user may be diverting additional attention to communicate on the phone, and a traffic accident often happens under that situation; therefore, it is very dangerous.
In order to avoid that situation, each company has launched its own audio receiving/transmitting device for their mobile communication apparatus, such as the hands-free phone. The device lets the users communicate without having to hold the mobile phones, thus freeing their hands to perform other functions. However, the conventional audio receiving/transmitting device still has a disadvantage. When the mobile phones receives an incoming call, the user still needs to push button on the mobile phones for answering the phone; then, the user can talk by the mobile phones. When ending the phone call, the user must also need to push buttons on mobile phones to hang up; therefore, the conventional mobile phones is still not convenient to use.